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Biomedical subjects

C Cope

Publications and source records attributed to C Cope.

At least 19 recordsLinked to original sources

Magnetic resonance imaging of angiographically occult runoff vessels in peripheral arterial occlusive disease.

BACKGROUND: Bypass grafting to arteries of the lower leg has become standard surgical management of advanced peripheral vascular disease. Its success depends on identifying suitable distal vessels. Preoperative preparation includes imaging of the arteries of the lower leg, usually by conventional contrast arteriography. An alternative procedure, magnetic resonance (MR) angiography, has been successfully employed in patients with various cardiovascular diseases, but its possible value in patients with peripheral vascular disease has received little attention. METHODS: We used both conventional and MR angiography in preoperative studies of the lower-leg vessels of 23 patients (25 legs) with peripheral arteriosclerosis and arterial insufficiency, and developed independent therapeutic plans based on the information provided by each technique. When the plans differed, the interventional procedure judged more likely to save the limb was performed. The findings of conventional and MR angiography were verified by intraoperative arteriography, postinterventional arteriography, or direct operative exploration. RESULTS: MR angiography detected all vessels identified by conventional angiography, whereas conventional arteriography failed to detect 22 percent of the runoff vessels identified by MR angiography. The detection by MR angiography of vessels not identified by conventional angiography altered the surgical management of the disorders of four patients (17 percent) and guided successful bypass procedures. CONCLUSIONS: MR angiography is a noninvasive technique with greater sensitivity than conventional contrast arteriography for detecting distal runoff vessels in patients with peripheral arterial occlusive disease.

Aged

Magnetic resonance angiography of peripheral runoff vessels.

Recent improvements in magnetic resonance imaging techniques have made magnetic resonance angiography (MRA) a very useful adjunct to invasive angiography. Fifty-five limbs in 51 patients with occlusive peripheral vascular disease were studied with both MRA and contrast arteriography. The magnetic resonance and contrast arteriograms were read by radiologists and surgeons and separate interventional plans were based on each study. The MRA findings differed significantly from those of conventional arteriography in 26 limbs (48%). In every case MRA visualized all of the same vessels and hemodynamic stenoses seen on the contrast arteriogram. In 48% of the cases, however, MRA revealed additional findings. Thus the discrepancies in the two studies were always the result of the failure of the arteriogram to reveal all of the patent vessels seen on MRA. The additional information provided by MRA resulted in alteration of the interventional plan in 11 cases (22%). In nine cases (18%) target vessels suitable for use in a limb-salvage procedure were identified by MRA, although they had been missed by conventional arteriography. In all of these cases, intraoperative arteriograms confirmed the suitability of these vessels for use in technically successful bypass procedures. In two cases (4%) additional information provided by MRA identified a target runoff vessel for bypass grafting that proved to be a better alternative than the one that would have been chosen on the basis of contrast arteriography.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Expandable intravascular catheter: percutaneous use for endoluminal retrievals.

Percutaneous use of an expandable vascular access catheter that can be deployed to temporarily occlude the entry vessel during retrieval of embolic material is described. The catheter was used to facilitate removal of two intraarterial objects, a postangioplasty free atheroma fragment and a displaced Gianturco coil. The expanded catheter end was equal to the arterial lumen, thus preventing distal embolization. The large distal lumen also facilitated plaque or foreign body removal by allowing deployment of various endovascular tools.

Aged

Prognostic significance of nuclear DNA content in phaeochromocytoma.

Nuclear DNA content of 27 phaeochromocytomas was measured by image analysis of thin sections and monolayer smears of nuclei extracted from thick sections (cytospins) using archival paraffin-embedded tissue blocks. Recurrence was assessed on the basis of clinical follow-up or urinary catecholamine levels. The mean follow-up was 5.0 years, with a range of 4 months to 15 years. Although it is not possible to differentiate accurately malignant tumours using DNA analysis, prediction of benign tumours is possible. Using thin sections, all tumours were benign when the percentage of cells with a DNA content of 2.5 c (2 c = diploid) was less than 40% and the DNA content of 5 c was less than 4%. Using the cytospin preparation, all diploid tumours were benign. Thus, patients with diploid tumours may be saved intensive long-term follow-up. Aneuploid and tetraploid tumours, however, continue to require careful lifelong follow-up.

Adolescent

Comparison of image analysis and flow cytometric determination of cellular DNA content.

A good correlation (r = 0.94) was obtained between the DNA indices (DI) using flow cytometry and image analysis of nuclei cytospins extracted from paraffin wax embedded tumour sections. Some of the limitations and problems associated with image analysis which came to light included an unacceptably high coefficient of variation (CV) and a "left-shift" in the DI in most DNA histograms obtained when using image analysis of 5 microns sections. In contrast, the DNA histograms generated using image analysis of cytospun nuclei from paraffin wax blocks were of good quality and similar to those obtained using flow cytometry. Variability in Feulgen staining was common and an important source of error despite rigorous control of the staining technique. This could be overcome by using internal controls such as fibroblasts rather than external controls (rat hepatocytes) to determine the diploid DI with image analysis. A thorough understanding and appreciation of the methodological problems associated with image analysis and flow cytometric determination of DNA content is required before these methods find widespread clinical application.

Adrenal Gland Neoplasms

Drainage of bile ducts with an articulated T tube.

An articulated T tube has been devised to simplify percutaneous replacement. Because the crosspiece and the stem are held together with sutures, they can be aligned over a catheter and guide wire for atraumatic insertion into the bile duct. By pulling the suture taut, the articulated T tube is easily reconstituted. A second suture can be attached to the proximal limb of the crosspiece to extract it end-on at a latter date without enlarging the tract. This articulated tube has been found very useful for safely replacing T tubes that have fallen out of immature tracts (n = 2) and inserting T tubes in tumor-encased bile ducts either via an existing T-tube tract (n = 1) or transhepatically (n = 1). This design extends the usefulness of T tubes for efficient intra- or extrahepatic bile duct drainage.

Aged

Method to control spraying of high-velocity infected blood droplets during arterial catheterization.

Spurting of blood from standard arterial needles during guide-wire insertion can be controlled easily with a syringe and a simple needle inserted along the syringe plunger. With this method, blood droplets that may be infected with the hepatitis or human immunodeficiency virus will not come into contact with the head and neck of the angiographer or interventional radiologist.

Acquired Immunodeficiency Syndrome

Percutaneous enterostomy with the Cope suture anchor.

Eighty-two percutaneous enterostomies were performed at three institutions with the Cope suture anchor for stomach or jejunal wall stabilization during alimentation tube placement. The anchors were successfully placed into the stomach or jejunum in 81 cases. Early in the series, two anchors were misplaced, with no sequelae. There were no other complications at the time of placement. In all successful cases, excellent immobilization of the viscus was achieved. Tract dilation and tube placement were easily performed, and there were no guidewire or tube dislodgments.

Adult

Percutaneous extraction of gallstones in 20 patients.

Percutaneous cholecystolithotomy (PCL) was accomplished successfully without general anesthesia in 17 of 20 consecutive symptomatic patients from an outpatient gallstone center who were at risk for or had refused cholecystectomy. The other three patients underwent cholecystectomy because of a gallbladder collapse before admission, a tight stone-bearing phrygian cap, and a cannula slippage, respectively. A subhepatic approach was preferentially used after the fundus of the gallbladder was stabilized with a percutaneous anchor to prevent invagination and bile leakage. Retrograde slippage of the anchor into the tract in the first six patients was remedied by elongating the anchor from 2 to 3 cm. Calculi were removed in one session (11 patients) or two consecutive sessions (six patients). Morbidity included rehospitalization for stitch infection (n = 1) and dehydration (n = 1), cannula slippage (n = 1), broken guide wire (n = 1), vasovagal reaction (n = 1), and unextractable anchors (n = 3). Gallbladder endoscopy enabled identification of stones not visible at cholecystography. Hospitalization lasted 3-5 days; outpatient gallbladder drains were removed in 2-3 weeks in 10 patients and 4-6 weeks in seven (older) patients. No retained stones were seen at 6 months. The authors recommend PCL for patients at risk for surgery.

Adult

Needle endoscopy in special procedures.

A needle endoscope, with a rigid shaft 2.2 mm wide and 20 cm long, an illumination range of 2-4 cm, and excellent optics, has proved to be very valuable in performing special interventional procedures because it can be inserted in any relatively straight 7-F catheter track. The needle endoscope has been very useful in combination with fluoroscopy for retracing lost drain tracks, evaluating fistulas and sinuses, performing limited pleuroscopy and laparoscopy for biopsy under direct vision, and evaluating the gallbladder and renal pelvis for location of duct openings. The author describes techniques used with the needle endoscope and results in a sample of cases. There has been no morbidity associated with the use of the instrument in over 800 examinations in a 12-year period.

Endoscopes